An ultrasonic liquid-height detector employs conductive rods extending from a housing, and corresponding transducers, into a liquid, where elastic seals surround the rods at their exit point from the housing. Acoustic crosstalk between the rods through the seals and the housing (rather than through the liquid) is minimized by displacing the seals from each other as measured through the housing to increase a path length through the housing so that the crosstalk energy is delayed with respect to the direct energy indicating liquid height. A sampling window is positioned to sample transmitted sound across the rods at a time before the arrival of the crosstalk energy.